Method of manufacturing and/or processing a paper, cardboard, or tissue web

ABSTRACT

A sealing device seals a pressure or vacuum zone of a roller having a roller sleeve which is movable in relation to the sealing device. The sealing device has a sealing strip with an upper side forming a sealing face and a lubricant channel adjoining the sealing face and is formed by at least one groove-type depression in the sealing strip, which extends in the longitudinal direction of the sealing strip. When the sealing device is installed, the sealing face and the opening of the groove-type depression face toward the inner side of the roller sleeve. The lubricant channel is hooked up to a supply line which at least in portions runs within the sealing strip and delivers lubricant between the inner side of the roller sleeve and the sealing face. The sealing strip, at each of its two ends, has a wall delimiting the lubricant channel in its length.

CROSS-REFERENCE TO RELATED APPLICATION

This is a divisional of copending patent application Ser. No.14/421,210, filed Feb.12, 2015 , which was a §371 national stage ofinternational patent application No. PCT/EP2013/066672 , filed Aug. 9,2013 ; this application also claims the priority, under 35 U.S.C. §119,of German patent application DE 10 2012 214 530.3 , filed Aug. 15, 2012;the prior applications are herewith incorporated by reference in theirentirety.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a sealing device for sealing a pressure orvacuum zone of a roller having a roller sleeve which is movable inrelation to the sealing device. The sealing device comprises a sealingstrip having an upper side which provides a sealing face and a lubricantchannel which adjoins the sealing face and is formed by at least onegroove-type depression in the sealing strip. The depression extends inthe longitudinal direction of the sealing strip. When the device isproperly installed in the roller, the sealing face and the opening ofthe groove-type depression face toward the inner side of the rollersleeve. The lubricant channel is hooked up to at least one supply linewhich at least in portions runs within the sealing strip and whichdelivers lubricant between the inner side of the roller sleeve and thesealing face.

Sealing devices in suctioned or blown rollers for paper-making,cardboard-making, or tissue-making machines have to reliably seal thepositive-pressure or negative-pressure zone in relation to theenvironment where normal pressure prevails. Here, in order to seal thepositive-pressure or negative-pressure zone, the sealing face of eachsealing strip of the sealing device is placed against the inner side ofthe rotating roller sleeve. In order to reduce wear of the sealing stripon account of friction between the sleeve face and the sealing face, theintroduction of a lubricant between the sealing face and the inner sideis attempted. This is usually done using injection pipes which, in therotation direction of the roller, are disposed ahead of the firstsealing strip of the positive-pressure or negative-pressure zone. Here,the lubricant is applied to the inner side of the roller sleeve andconveyed by said roller sleeve by way of its rotation to the individualsealing strips, on account of which, when viewed in the rotationdirection, the lubricant supply decreases from sealing strip to sealingstrip. In order to nevertheless supply the downstream sealing strips inthe rotation direction with sufficient lubricant, a large amount oflubricant has to be used, only a small part thereof benefiting thelubrication of the sealing strips per se however, and otherwisecontributing toward the undesirable re-humidification of the fibrousweb.

SUMMARY OF THE INVENTION

In order to solve this problem, the applicant proposes an inventionwhereby the lubricant is directly guided to the upper side of therespective sealing strip which provides the sealing face, so that eachindividual sealing strip is supplied in a targeted manner with therequired amount of lubricant. A preferred design embodiment of thisinvention further proposes here a lubricant channel in the form of agroove-type depression, which, extending in the longitudinal directionof the sealing strip, i.e. in the machine cross direction of the roller,is provided on the upper side of the roller and which is disposed besidethe sealing face. Surprisingly, it has emerged that in comparison withusual amounts, adequate lubrication can be achieved even with modestamounts, of lubricant. Initial experiments of the applicant of theabovementioned invention were carried out using sealing strips having alubricant channel which is open on two ends on the longitudinal side ofthe sealing strip. It has been demonstrated that using thisconfiguration, the lubrication performance indeed may be significantlyimproved at significantly lower lubricant consumption, but that undercertain circumstances a lubricating effect which is irregular across thelength of the sealing strip and which can only be leveled out by anincrease—indeed below the known level—in the amount of lubricant, isachieved.

It is thus the object of the present invention to propose a sealingdevice which comprises at least one sealing strip, in which thelubricant consumption can be further reduced while maintaining ahomogeneous lubricating effect, when viewed across the length of thesealing strip.

The object is achieved by a sealing device for sealing apositive-pressure or negative-pressure zone of a roller having a rollersleeve which is movable in relation to the sealing device, wherein thesealing device comprises a sealing strip which in its length isdelimited by two ends and which has an upper side, and the upper sideprovides a sealing face and a lubricant channel which adjoins thesealing face, wherein the lubricant channel is formed by at least onegroove-type depression in the sealing strip, which extends in thelongitudinal direction of the sealing strip, and in the case of theinstallation of the sealing device in the roller according to theintended use, the sealing face and the opening of the groove-typedepression face toward the inner side of the roller sleeve, wherein thelubricant channel is hooked up to at least one supply line which atleast in portions runs within the sealing strip and by means of which alubricant is deliverable between the inner side of the roller sleeve andthe sealing face, wherein the sealing strip in its length is delimitedby two ends. The invention is characterized in that the sealing strip inthe region of its two ends has in each case one wall which closes offthe lubricant channel in its length.

On account of the lubricant channel being closed off in its length onboth sides, the former is configured so as to be tub-like, on account ofwhich a level of lubricant which is uniform across the length of thelubricant channel can be reached and the lubricant channel forms a typeof reservoir for the lubricant. On account thereof, a substantiallyconstant level of lubricant can be maintained, even in the case ofvariable dispensing of lubricant by the supply line. On account thereof,the amount of required lubricant can be further reduced and the failsaferunning functions in the case of a short-term outage of the lubricantsupply can be improved. On account thereof, the operating costs causedby lubricant consumption are not only significantly reduced, butre-humidification of the fibrous web, in particular the paper,cardboard, or tissue web, is also significantly reduced, since inabsolute terms less lubricant has to be employed for an adequatelubricating effect and, on account of the lubricant channel being closedat both ends, less lubricant runs off unused and can make its way viabores in the roller sleeve to the fibrous web.

Advantageous design embodiments and refinements of the invention arestated in the dependent claims.

Preferably, the lubricant channel extends substantially across theentire length of the sealing strip. Substantially here is to mean thatthe lubricant channel extends across at least 90% of the length of thesealing strip. Here, the sealing strip may extend in an uninterruptedmanner. The two walls delimiting the lubricant channel in its lengthpreferably have a thickness, when viewed in the longitudinal directionof the sealing strip, of 20 cm maximum, preferably 10 cm maximum. In thecase of a usual sealing strip, this may mean that the lubricant channelextends across a plurality of meters, whereas the two walls at the endsof the sealing strip in each case extend across 20 cm maximum, inparticular 10 cm maximum.

In order to design the construction of the sealing device in a simplemanner in respect of the hook-up of the supply line to the sealing stripand to nevertheless ensure uniform deployment of the lubricant acrossthe length of the sealing strip, a preferred design embodiment of theinvention provides that the supply line comprises a central supply ductwhich extends within the sealing strip along the longitudinal directionof the latter, and at least one riser line, preferably a plurality ofriser lines, which interconnect(s) the lubricant channel and the centralsupply duct and via which the lubricant channel is fed with thelubricant by way of outlet openings of the respective riser line, whichend in the lubricant channel. According to this design embodiment, thecentral supply duct can be fed with the lubricant by way of one or a fewsupply lines. The central supply duct then distributes the lubricant toa plurality of riser lines—wherein the number of riser lines issignificantly higher than the number of supply lines. It is conceivablein this context for there to be an outlet opening disposed about every 5to 500 mm, when viewed in the longitudinal direction of the sealingstrip.

In order to be able to furthermore better homogenize the deployment ofthe amount of lubricant and to hereby provide a solution from theconstruction and the manufacturing-engineering point of view, a furtheradvantageous design embodiment of the invention provides that thecentral supply duct, along its longitudinal extent, has a variablecross-sectional area and/or cross-sectional geometry. This designembodiment of the invention may also represent an autonomous inventivesolution. Such a central supply duct having a variable cross section maybe manufactured in a particularly simple manner in that, for example,initially a groove, for example a U-shaped groove, which is open towardone of the long sides of the main body, is incorporated into the mainbody of the sealing strip, the opening of which groove is then closedoff using sealing-strip material, and then partially closed off forexample by means of a profiled body reproducing the width and length ofthe groove, but not the latter's depth. This profiled body may then befastened on the main body by way of adhesive bonding, for example, and,together with said main body, configure a duct which provides thecentral supply duct.

In order to achieve an effective lubricating effect, a preferred designembodiment of the invention provides that the sealing face and thelubricant channel are disposed on the upper side in such a manner that,in the case of the installation of the sealing device in the rolleraccording to the intended use, when viewed in the envisaged rotationdirection of the roller sleeve, the lubricant channel is disposedupstream of the substantial part of the sealing face, in particular thatthe lubricant channel is disposed upstream of the entirety of thesealing face. On account thereof, it is achieved that the inner side ofthe roller sleeve is wetted with the lubricant directly before saidinner face runs onto the sealing face or at least the substantial partof the sealing face.

Where reference is made in the context of this application to theoperation of the sealing device in the roller according to the intendeduse, this is to be understood to be the operating state in which thesealing strip with its sealing face is placed against the inner side ofthe roller sleeve in such a manner that a sealing effect is achieved.

A further preferred design embodiment of the invention provides that thesealing strip is delimited in its width by a front and a rear end side,and the upper side of the sealing strip extends between the front andthe rear end side, wherein the front and rear end sides, and the sealingface, and the lubricant channel, are disposed in such a manner that, inthe case of the installation of the sealing device in the rolleraccording to the intended use, and when viewed in the envisaged rotationdirection of the roller sleeve, the roller sleeve runs onto the sealingstrip in the region of the front end side, initially sweeps thelubricant channel and subsequently the sealing face, so as to run offthe sealing strip in the region of the rear side.

When viewed in a sectional plane which is perpendicular to thelongitudinal extent of the sealing strip, the lubricant channel displaysa bed which forms the lowest point of the lubricant channel and whichhas a front side wall which extends to the front end side, and a rearside wall which extends to the sealing face. Here, the upper edge of thefront side wall in particular adjoins the front end side, and the upperedge of the rear side wall in particular adjoins the sealing face. It ispreferably provided that in the case of the installation of the sealingdevice in a roller according to the intended use, a straight lineinterconnecting the two upper edges forms an angle of 1° to 89° with thehorizontal, in particular an angle of 15° or more and 80° or less.

On account thereof, the straight line interconnecting the two upperedges forms a type of wedge-shaped gap between the upper side of thesealing strip and the inner side of the roller sleeve, which is largestat the front end side and tapers off toward the sealing face. On accountthereof, a suction effect is achieved by the air entrained by therotating roller sleeve, which draws the lubricant along into the gapbetween the inner side of the roller sleeve and the sealing face.

According to a specific design embodiment of the invention, in the caseof the installation of the sealing device in the roller and theoperation thereof according to the intended use, when viewed in theradial direction of the roller, the rear end side then extends so as tobe closer to the inner side of the roller sleeve than the front endside; in particular, the rear end side extends up to the inner side ofthe roller sleeve, whereas the front end side does not extend up to theinner side of the roller sleeve.

According to a potential design embodiment of the invention, the frontand the rear sides of the sealing strip extend so as to be substantiallyparallel with one another.

A further preferred design embodiment of the invention provides that thesealing device comprises a sealing-strip holder for holding the sealingstrip, wherein the sealing-strip holder has a holding portion having atleast one guide face on which the sealing strip by way of at least oneof the two sides of front and rear side is displaceably mounted, onaccount of which the sealing strip, in the case of the installation ofthe sealing device in the roller according to the intended use, whenviewed along a path in the radial direction of the roller, isdisplaceable from and to the inner side of the roller sleeve face,wherein the supply line at at least one point on one of the two endsides is routed out of the sealing strip, and wherein the holdingportion has at least one clearance through which that portion of thesupply line that is routed out of the end side of the sealing strip isrouted through the sealing-strip holder, and wherein the at least oneclearance is configured in such a manner that the sealing strip ismovable along the path in relation to the sealing-strip holder togetherwith the portion of the supply line which is routed out thereof.

It is conceivable for the at least one clearance to be configured so asto be hole-shaped or as a groove which is open toward the top.

According to another independent aspect of the invention, a rollercomprising at least one positive-pressure or negative-pressure zonehaving at least one sealing device as claimed is described.

It is preferably provided that the part of the supply line which runsoutside the sealing strip but within the roller has a flexurally rigidfirst line portion and a second line portion which in relation to theformer is flexural, or is configured therefrom, respectively. Here, theflexural second line portion is significantly shorter than theflexurally more rigid first line portion.

On account of the flexural, short second line portion, freedisplaceability of the sealing strip in relation to the sealing-stripholder is ensured in the radial direction of the roller, toward theinner side of the roller sleeve or away therefrom. The first lineportion of the part of the supply line which runs within the roller butoutside the sealing strip may be configured so as to be flexurally rigidand thus stable. When conceiving and disposing the flexural second lineportion, attention has to be paid, in particular, to said flexuralsecond line portion running such that it does not chafe on componentswithin the roller when the sealing strip moves. Steel pipes, forexample, may be used for the first line portion. For the second lineportion a rubber tube may be used, for example, which may be reinforcedwith steel braiding, for example.

It is particularly conceivable that the flexurally rigid first lineportion commences at the at least one roller end and extends in theroller in the direction of the sealing strip. It is further conceivablethat the flexural second line portion commences so as to be spaced atone meter maximum from the at least one point at which the supply lineis routed out from the sealing strip. In order to be able to at leastallow for the travel of the sealing strip due to wear, it is inparticular conceivable that the flexural second line portion has alength in the range of 15 cm to 200 cm, in particular has a length inthe range of 20 cm to 200 cm.

It is further conceivable for each of the two roller ends to comprise aroller cap, and for the supply line to be routed out of the roller at atleast one of the roller caps.

The flexural second line portion preferably commences at that point atwhich the supply line is routed out of the sealing strip.

The supply line preferably displays a fourth line portion, to which thecentral supply duct and the at least one riser line may belong, forexample, which is integral to or is unreleasably connected to thesealing strip, and a third line portion which is releasably connected tothe fourth line portion and which runs outside the sealing strip andpreferably is routed to at least one of the two roller ends. On accountthereof, it is enabled that the sealing strip, for example when beingreplaced or during maintenance, can be readily hooked up to thelubricant supply and separated therefrom again.

Preferably, in the region of the at least one point at which theconnecting line is routed out of the sealing strip, at least oneconnecting element, for example in the form of a bush which is sealed byan O-ring, by means of which the third and the fourth line portions arereleasably interconnected, is provided in this case, that is to say thataccording to this embodiment, the fourth line portion extendssubstantially within the sealing strip and terminates at the connectingelement. The third line portion then is routed outside the sealing stripand is releasably connected to the fourth line portion by way of the atleast one connecting element. It is quite possible for the fourth lineportion to run within the sealing strip in such a branched manner thatsaid fourth line portion is routed out of the sealing strip at aplurality of points which are disposed beside one another in thelongitudinal direction of the sealing strip, for example. In this case,preferably one connecting element by means of which the respectivebranch is connected to the third line portion is then disposed in theregion of each point at which a branch of the fourth line portion isrouted out of the sealing strip.

The third line portion preferably is made up of the first and the secondline portions.

The lubricant preferably is substantially water. The term“substantially” here refers to the potential possibility of addinglubricant additives to the water, wherein water always represents themajor component of such a mixture (in relation to percent per volume).

According to a further independent aspect of the invention, a method formanufacturing and/or processing a paper, cardboard, or tissue web usinga paper-making, cardboard-making, or tissue-making machine, in which thepaper, cardboard, or tissue web is manufactured or processed at aproduction speed of 500 meters per minute or more, and the web, togetherwith a paper-making machine covering, is at least in portions guidedover at least one roller having a perforated roller sleeve and at leastone positive-pressure or negative-pressure zone, wherein thepositive-pressure or negative-pressure zone is sealed by at least onesealing device having at least one sealing strip and at least one of theat least one sealing strip has an upper side which faces toward theinner side of the roller sleeve and which provides a sealing face whichis placed against the inner side of the roller sleeve, and at least onelubricant outlet opening, wherein by means of the lubricant outletopening a lubricant is introduced between the sealing face and the innerside of the roller sleeve, is proposed. The method according to theinvention is characterized in that the amount of lubricant used permeter of machine width and per minute is four liters or less, inparticular three liters or less, in particular one liter or less.

The inventors have established that sealing strips in which thelubricant is disposed on the upper side which faces toward the innerside of the roller sleeve not only achieve an improved lubricatingeffect with less wear of the sealing face of the sealing strip, but thatin the case of production speeds (also referred to as machine speeds) of500 meters per minute or more, the consumption of lubricant, inparticular substantially water, of often 10 to 15 liters per meter ofmachine width and minute can be reduced to less than one liter or lessper meter of machine width and minute. On account thereof, not only theoperating costs caused by lubricant consumption are significantlyreduced, but re-humidification of the paper, cardboard, or tissue web isalso significantly reduced. The inventors have recognized that bycombining machine speeds of 500 meters per minute or more and the use ofat least one of the sealing strips having lubrication in the region ofthe sealing-strip upper side, the lubricating effect, on account of thesuction effect at high production speeds, can be further increased insuch a manner that an amount of lubricant of one liter per meter ofmachine width and per minute is sufficient for adequate lubrication.

The lubricant preferably is substantially water. The term“substantially” refers here to the potential possibility of addinglubricant additives to the water, wherein water always represents themajor component of such a mixture (in relation to percent per volume).

Experiments of the applicant moreover have unexpectedly demonstratedthat energy consumption can also be reduced by more than 5%, caused bythe significantly more efficient lubrication of the frictional pairingof the sealing face of the sealing strip and the inner side of theroller sleeve.

Preferably, the production speed is 700 meters per minute or more.

In order to further improve the lubricating effect, a refinement of themethod according to the invention proposes the use of at least onesealing device as described, in the method.

Preferably, all sealing strips of the sealing device are equipped withan upper side which faces toward the inner side of the roller sleeve andwhich provides a sealing face and a lubricant outlet opening for thelubricant by way of which lubricant is introduced in each caseseparately and independently between the respective sealing face and theinner side of the roller sleeve.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The invention is explained in more detail in the following by means ofschematic drawings which are not to scale.

FIG. 1 shows a sealing strip of a sealing device according to theinvention, in a plan view;

FIG. 2 shows a roller according to the invention, in a sectional planewhich is perpendicular to the longitudinal extent of the roller, havingthe sealing strip from FIG. 1; and

FIG. 3 shows a detail of the roller of FIG. 2, in the region of one ofits longitudinal ends, in a plan view.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a sealing strip 1 of a sealing device according to theinvention, in a plan view onto the upper side 2 of the sealing strip 1,which in the case of the installation of the sealing device in a rolleraccording to the intended use faces toward the inner side of a rotatableroller sleeve.

The upper side 2 of the sealing strip 1 provides a sealing face 3 (drawnusing hatched lines) and a lubricant channel 4 which adjoins the sealingface 3, wherein the lubricant channel is formed by at least onegroove-type depression in the sealing strip, which extends in thelongitudinal direction L of the sealing strip 1, and in the case of theinstallation of the sealing device in the roller according to theintended use, the sealing face 3 and the opening of the lubricantchannel 4 face toward the inner side of the roller sleeve. It is to benoted at this point that in the case of the installation of the sealingdevice 9 in the roller 8 according to the intended use, the longitudinaldirection L of the sealing strip 1 and the longitudinal direction of theroller coincide and are in each case separately and also commonlyreferred to with the reference sign L. The length of the sealing strip 1is to be understood as its maximum extent in the longitudinal directionL.

As can be derived from the illustration of FIG. 1, a multiplicity oflubricant outlet openings 5 of a supply line 12 for supplying lubricant,which are disposed behind one another in the longitudinal direction ofthe lubricant channel 4 terminate in the lubricant channel 4. Thesealing strip 1 in its length is delimited by two ends 6.1 and 6.2. Thesealing strip 1 according to the invention, in the region of its twoends 6.1 and 6.2, displays in each case one wall 7.1 and 7.2, delimitingthe lubricant channel 4 in its length. The sealing strip 1 has a lengthof a multiplicity of meters, and each of the two walls 7.1 and 7.2, whenviewed in the longitudinal direction L of the sealing strip 1, has athickness of 20 cm or less, in particular 10 cm or less.

FIG. 2 shows a roller 8 according to the invention, in a sectional planewhich is perpendicular to the longitudinal extent L of the roller 1. Asealing device 9 according to the invention, having the sealing strip 1shown in FIG. 1, is installed in the roller 8 according to the intendeduse. FIG. 2 shows the sealing device 9 having the sealing strip 1 in theposition in which the sealing face 3 thereof is placed against the innerside 11 of the roller sleeve 10, in order to seal a positive-pressurezone or negative-pressure zone (not shown). FIG. 3 shows a roller end onthe longitudinal side in a plan view, without an illustration of theroller sleeve, wherein components which run within the roller 8 aredrawn using dashed lines.

The lubricant channel 4 is hooked up to a supply line 12 which inportions runs within the sealing strip 1 and which, on the side of thesealing strip, terminates at the lubricant outlet openings 5 and bymeans of which lubricant 31, which is located in the lubricant channel4, is deliverable between the inner side 11 of the roller sleeve 10 andthe sealing face 3.

As can be derived from the illustration of FIG. 2, the sealing face 3and the lubricant channel 4 are disposed on the upper side 2 in such amanner that in the case of the installation of the sealing device 9 inthe roller 8 according to the intended use and during rotation of theroller sleeve 10 in the envisaged rotation direction D, the lubricantchannel is upstream of the substantial part of the sealing face 3, inthe present case even upstream of the entirety of the sealing face 3.

The sealing strip 1, in its width B, is delimited by a front end side 24and a rear end side 15 which runs substantially parallel therewith,between which the upper side 2 of the sealing strip 1 extends. Here, thefront and rear end sides 24, 15, and the sealing face 3, and thelubricant channel 4, are disposed in such a manner that in the case ofthe installation, shown in FIG. 2, of the sealing device 9 in the roller8 according to the intended use and during rotation of the roller sleevewhen viewed in the envisaged rotation direction D, the roller sleeve 10runs onto the sealing strip 1 in the region of the front end side 24,initially sweeps the lubricant channel 4 and subsequently the sealingface 3, so as to run off the sealing strip 1 in the region of the rearend side 15.

One can furthermore see that, when viewed in the radial direction R ofthe roller 8, the rear end side 15 extends so as to be closer to theinner side 11 of the roller sleeve 10 than the front end side 24, onaccount of which an inlet gap is formed between the upper side 2 of thesealing strip 1 and the inner side 11 of the roller sleeve 10 in theregion of the front end side 24.

The sealing device 9 furthermore comprises a sealing-strip holder 25 forholding the sealing strip 1. The sealing-strip holder 25 here presentlyhas a holding portion having two guide faces 26, 27 on which the sealingstrip by way of its two sides 15, 24 is displaceably mounted, so as tobe displaceable from the front or rear end side in the radial directionR of the roller 8 along a path from and to the inner side 11 of theroller sleeve face 10. The sealing-strip holder 25 furthermore has abase 29 on which a bellows 30, which is filled with a pressure mediumsuch as, for example, air, is supported and by means of which thesealing strip 1 is movable in relation to the sealing-strip holder 25 inthe direction R.

It furthermore can be identified that the supply line 12 is routed outof the sealing strip 1 at at least one point 28 at the rear end side 15.In order to ensure free displaceability of the sealing strip 1 inrelation to the sealing-strip holder 25, when viewed in the radialdirection R of the roller 8, the holding portion has at least oneclearance 32 which is configured so as to be hole-shaped and throughwhich the portion of the supply line 12 which is in each case routed outof the rear end side 15 of the sealing strip 1 is routed through thesealing-strip holder 25.

As can be identified from the illustration of FIG. 2, the supply line 12comprises a portion which is routed within the sealing strip, and aportion which is routed outside the sealing strip 1. The portion of thesupply line 12, which is routed within the sealing strip 1 comprises acentral supply duct 13 which extends in the longitudinal direction L ofthe sealing strip 1 and from which a plurality of riser lines 14 whichare disposed behind one another in the longitudinal direction L of thesealing strip 1 and which in each case terminate at a lubricant outletopening 5 in the lubricant channel 4 emanate. One or a plurality ofpresently horizontally routed line portions which on the rear end side15 is/are routed out of the sealing strip 1 branch off from the centralsupply duct 13. It is conceivable that the central supply duct 13 alongits longitudinal extent L has a variable cross-sectional area and/orcross-sectional geometry.

The portion of the supply line 12 which runs outside of the sealingstrip 1 but within the roller 8 comprises a first line portion 21 and asecond line portion 22, as shown in FIGS. 2 and 3. Here, the first lineportion 21 is longer than the second line portion 22, and the secondline portion 22 is configured so as to be flexural in comparison withthe first line portion 21. Presently, the second line portion 22 isformed by a braided metal hose 22. Furthermore, the second line portion22 commences in a region of at maximum one meter, calculated from thepoint 28 at which the supply line 12 is routed out from the sealingstrip 1, and preferably has a length of 20 to 100 cm, preferably up to80 cm. The first line portion 21 terminates at one of its longitudinalends at a longitudinal roller end 23, which is configured as a rollercap, for example, and at its other longitudinal end at a connectingpiece 20.

The first and the second line portions 21, 22 together form a third lineportion 18. That part of the supply line 12 that runs within the sealingstrip 1, and a short line piece which runs between the central supplyduct 13 and the point 28 form a fourth line portion 17. The fourth lineportion 17 is unreleasably connected to the sealing strip 1 and forms anintegral part of the latter. Since it is a fixed component of thesealing strip 1, here the fourth line portion 17 is removed andinstalled along with the sealing strip 1 when the latter is removed orinstalled; the third and the fourth line portions 18, 17, are releasablyinterconnected by way of the connecting element 20.

1. A method of manufacturing and/or processing a paper, cardboard, ortissue web using a paper-making, cardboard-making, or tissue-makingmachine, the method which comprises: processing or manufacturing thepaper, cardboard, or tissue web at a production speed of at least 500meters per minute or more, and guiding the web, together with apaper-making machine covering, at least in portions a roller having aperforated roller sleeve and a pressure or vacuum zone; sealing thepressure or vacuum zone with a sealing device having at least onesealing strip with an upper side facing toward an inner side of theroller sleeve, and, during the sealing operation, placing the upper sideto form a sealing face against the inner side of the roller sleeve; andfeeding a lubricant from at least one lubricant outlet opening betweenthe sealing face and the inner side of the roller sleeve at an amount oflubricant per meter of machine width and per minute of four liters orless.
 2. The method according to claim 1, which comprises feeding thelubricant in an amount per meter of machine width and per minute ofthree liters or less.
 3. The method according to claim 1, whichcomprises feeding the lubricant in an amount per meter of machine widthand per minute of one liter or less.
 4. The method according to claim 1,wherein the lubricant is primarily water.
 5. The method according toclaim 1, wherein the roller is a suction roller.
 6. The method accordingto claim 1, wherein the sealing strip has a length delimited by two endsand a respective wall integrally formed at each of the two endsdelimiting a length of the lubricant channel.
 7. The method according toclaim 1, wherein an upper side of the sealing strip has a groove formedtherein defining a lubricant channel and being delimited by end wallsintegrally formed with the sealing strip.